I have mentioned this valuable free tool before — VirusTotal.com

Virus Total was purchased by Google a few years back. It allows you to easily upload a file from your computer or type (paste) a website address to check them against 50+ anti-malware services. There is no software to install to use this service. Simply access the website via your browser. Don’t depend on your local anti-virus software for everything.

If you have suspicions about a website or file, be proactive. Your first line of defense is not a software package that won’t keep you safe 100% of the time. Your best strategy is defensive computing.